Apparatus for driving a recording instrument

ABSTRACT

Mechanism for driving an odometer for logging footage drilled by an oil well drill or the like, and including a clutch driven by a measuring line, a shaft driven through the clutch, a sleeve telescoped onto the shaft and carrying a sprocket that drives the odometer through a chain, and a one-way coupling for turning the sleeve only as the shaft is driven forwardly. The one-way coupling includes a cage which turns with the sleeve, and gearing acts between the cage and the shaft as a spline coupling during forward rotation, but during reverse rotation of the shaft, the cage is held stationary and the gearing rotates a signal arm from a normal, idle position into a blocking position over an orifice to block air flow therefrom and create a pressure signal for actuating a cylinder for disengaging the clutch, and shifting a plunger of a driller&#39;&#39;s control valve. The signal arm is returned to its idle position, and the clutch remains disengaged until the plunger is pushed in manually to reactivate the driving mechanism.

United States Patent [01 3,739,888 Brady June 19, 1973 1 APPARATUS FORDRIVING A RECORDING Primary Examiner-Allan D. l-lerrmann INSTRUMENT [75]Inventor: James .1. Brady, Glendale, Calif.

73 Assigneet Technica1'0i1Too1 Corporation, 1'

'Glendale, Calif. Filed: Jan. 31, 1972 Aral- 5 12221270 I a [5 6]References Cited UNITED STATES PATENTS 5/1954 Yancey 73/1515 10/1961Phillips 346/33 WL X 11/1961 Abs et a1 3/1968 Wyszyinski 73/1515 3/1968Redwine 73/1515 Attorney-Thomas M. Small [57] ABSTRACT Mechanism fordriving an odometer for logging footage drilled by an oil well drill orthe like, and includinga clutch driven by a measuring line, a shaftdriven through the clutch, a sleeve telescoped onto the shaft andcarrying a sprocket that drives the odometer through a chain, and aone-way coupling for turning the sleeve only as the shaft is drivenforwardly. The oneway coupling includes a cage which turns with thesleeve, and gearing acts between the cage and the shaft as a splinecoupling during forward rotation, but during reverse rotation of theshaft, the cage is held stationary and the gearing rotates a signal armfrom a normal, idle position into a blocking position over an orifice toblock air flow therefrom and create a pressure signal for actuating acylinder for disengaging the clutch, and shifting a plunger of adrillers control valve. The signal arm is returned to its idle position,and the clutch remains disengaged until the plunger is pushed inmanually to reactivate the driving mechanism.

11 Claims, 6 Drawing Figures APPARATUS FOR DRIVING A RECORDINGINSTRUMENT BACKGROUND OF THE INVENTION minute written record or log of anumber of factors regarding the drilling unit, usually including thetotal weight in suspension, torque, fluid pressure, speed of rotation,the rate of penetration, and thetotal penetration or depth of the hole.Information regarding such factors enablesthe-drilling operator tocontrol the drilling unit' with optimum precision. and a minimum oftrouble. This invention has specific reference to the logging of thepenetration of the, drilling tool.

Various types of drilling recorders have been used in the past to logthe downward travel of a drilling tool, and. customarily are operatedbya flexible steel cable, or so-called measuring line, which is stored onan above-ground reel, extends around pulleys on the derrick of the rig,and has a free end fastened to a member that moves downwardly with thedrill string during the drilling operation, typically a'so-calledgooseneck on a swivel at the upper end of the Kelly by which the drillstring is rotated as it is lowered into the hole. Thus, the linealtravel of the; measuring line is a direct indication of the travel ofthe drill bit, and is used to drive an in.- strument such as anodometer, or sometimes a chart recorder, for recording total drilledfootage.

Innormal drilling operations, there are many circumstances which requireraising of the drill string within the hole and subsequent lowering ofthe string for really by the driller, through a suitable control locatedsomewhere near the drilling rig. Because of the danger of a failure todo so through oversight, and also because of the inconvenience ofteninvolved when the control is not conveniently located relative to thedrillers station, there has been a, need for a reliable automatic devicefor controlling the drilling recorder.

SUMMARY: OF THE INVENTION The present invention resides in a novelapparatus for driving a recording instrument during forward or drillingtravel of the tool,,deactivating the instrument automatically as anincident to the beginning of reverse travel of the tool,and'reactivating the instrument preparatory to the resumption ofdrilling. To these ends, the driving apparatus has an input shaftadapted to be coupled by a clutch member to the drilling tool formovement in accordance with lineal movement of the tool, and has a drivecoupling for connection to the recording instrument to drive the latterduring forward motion of the tool. The drive coupling is driven by theinput shaft during such forward motion, but reverse travel of the toolacts through the input shaft to disengage the clutch and leave therecording instrument deactivated, with an indicated footage that is thesame as that attained prior to reversal of the tool travel.

Then, all subsequent travel of the tool, both reverse travel andsubsequent forward travel necessary to return the tool to the bottom ofthe hole, occurs without registering any of such motion on the recordinginstrument. When the tool has been returned to the hole bottom anddrilling is about to be resumed, the driller manually reactivates thedriving apparatus and the recording instrument as he initiates the restof the operations for resuming normal drilling.

More specifically, and as illustrated in the preferred embodiment shownherein, the drive coupling is carried by a sleeve which is rotatablysupported on the input shaft and is connected to the latter by a one-waycoupling which drives the sleeve, and thus the recording instrument,during forward rotation of the shaft but, upon reverse rotation of theshaft, does not drive the sleeve reversely. Instead, the sleeve isfrictionally held against turning, and such reverse rotation of theshaft drives gearing in the coupling which moves a normally idlesignalarm into position to produce a signal for disengaging the clutchmember to uncouple the input shaft from the tool, and the entire drivingapparatus is simultaneously returned to a ready position from which itcan resume recording as soon as the clutch member is re-engaged by thedriller.

I Other aspects and advantages of the invention will become apparentfrom the following detailed description, taken in conjunction wiith theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary view, partlyin cross-section and partly in side elevation, of a recorder drivingapparatus and related structure embodying the novel features of thepresent invention;

FIG. 2 is an enlarged fragmentary view of the basic parts of the drivingapparatus of FIG. 1, with additional portions broken away and shown incross-section;

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a fragmentary cross-sectional view taken along line 5-5 ofFIG. 2; and

FIG. 6 is a schematic flow diagram of the basic parts of a simplifiedcontrol system for the driving apparatus.

DETAILED DESCRIPTION As shown in the drawings for purposes ofillustration, the invention is embodied in an apparatus, indicatedgenerally by the reference number 10, for driving a recording instrumentsuch as an odometer 11 which logs the total footage drilled by an oilwell drilling tool represented by the box T in FIG. 1. The apparatus ismounted in a case 12 that is positioned near the drilling rig and has ahousing 13 on one side with a pulley 14 therein, around which ameasuring line 15 is trained. The measuring line is connected in theusual manner to the drilling tool for movement in accordance with lineartravel of the tool, and thus turns the pulley and its supporting shaft17 back and forth as the tool is lowered and raised.

In general, the driving apparatus 10 comprises a clutch 18 having aninput member 19 rotatable with the pulley shaft and an output member 20,a shaft assembly connected to the output member at oneend and journaledin a bearing 21 on the case 12 at its other end, and a drive coupling 22on the shaft assembly for driving the odometer 11 through an endlesschain 23. A

pneumatic cylinder 24 mounted inside the case 12 has a piston rod 25which, when extended upwardly, rocks an actuating arm 27 clockwise aboutits pivot 28 to disengage the cluch 18 by moving the output member 20downwardly away form the input member. This uncouples the shaft assemblyand the odometer 11 from the measuring line pulley 14. The cylinder 24preferably is of the type in which the rod 25 is extended by airpressure and retracted by a return spring (not shown) when the pressureis relieved.

As shown most clearly in FIG. 2, the drive coupling 22 comprises asprocket around which the endless chain 23 is trained, and an elongatedtubular sleeve 29 on which the sprocket is mounted, the clutch member 20being fastened on the upper end of a sleeve forming a tubular hub 20afor the clutch member 20 and carrying an annular collar 30 which isengaged by the free end of the actuating arm 27. A shaft 31 of the shaftassembly extends loosely through both the clutch menber 20 and thesleeve 29, but is keyed to the clutch member 20 by a pin 32 (FIG. 2)projecting into an axially elongated slot 33 in the hub 20a of theclutch member 20 so that the latter and the shaft turn together but areaxially movable relative to each other. The lower end of the hub 20aabuts rotatably against the end of the sleeve 29 adjacent the sprocket.1

The sleeve 29 is both slidably and rotatably mountedon the shaft 31, andis urged upwardly relative to the shaft by a coiled spring 34 telescopedover the shaft, inside the sleeve, and compressed between an internal,downwardly facing shoulder 35 on the sleeve and an upwardly facingshoulder 37 around the shaft, thus normally holding the clutch members19 and 20 in frictional, coupled engagement. Plastic lubrication andcentering rings 38 preferably are disposed between the shoulders 35 and37 and the opposite ends of the spring 34.

To rotate the sleeve 29 and drive the odometer 11 during drilling travelof the drilling tool, the sleeve is drivingly connected to the shaft 31by a one-way coupling, indicated generally by the number 39, actingbetween the shaft and the lower end of the sleeve to turn the sleevewith the shaft in one direction of rotation of the shaft, the directionindicated by the arrows 40 in FIGS. 1 and 2. This is the forwarddirection .of rotation produced by forward or drilling travel of thedrilling tool.

During such forward rotation, the sleeve 29 is driven in the samedirection by the one-way coupling 39, thereby turning the sprocket at aratecorresponding to the rate of lineal travel-of the drilling tool, todrive the odometer 11 and record the footage drilled by' the tool.During reverse rotation of the shaft, produced by the measuring line 15and-the pulley 14 as the toolisraised, the shaft turns reversely withinthe sleeve, ,which're' mains stationary in the position which it hadattained when forward rotation ceased. Accordingly, the odom-v eterremains in th condition achieved prior to the reversal of the tool, andretains the footage reading which indicates the previously-achievedtotal depth of penetration.

Animportant" aspect 6f: the presentinvention I is the construction andoperation, of the one-way coupling 39, which .is designed not only topermit the shaft 31 to turn reversely relative to the drive coupling 21,but also to produce a signal for actuating the cylinder 24 to'disengagethe clutch 18 as an incident to such reverse turning. The coupling 39deactivates the driving appa-' ratus for the duration of themanipulation of the drilling tool, while leaving the apparatus incondition for reactivation when the tool has been returned to the bottomof the hole and is ready for the resumption of drilling.

For these purposes, the one-way coupling 39 includes a housing or cageformed by two disk-shaped end-walls 41 which are mounted on the lowerend of the sleeve 29 for rotation therewith about the drive shaft 31,the upper endwall being fastened to the sleeve 29 and connected to thelower endwall by a plurality of fasteners 42, including spacer sleeves,and a cylindrical sidewall 47 which encloses the interior of the cage. Aplanetary gear 43 is mounted in the cage on a shaft 44 in spacedparallel relation with the drive shaft, and a pinion gear 45 is pinnedto the drive shaft to turn with the shaft in meshing engagement with theplanetary gear 43.

in addition, the one-way coupling 39 includes means for preventingrotation of the gears 43 and 45 in one direction from a preselectedangular relation so that the gears act as a positive spline connectionin one direction in this angular relation, but are relatively rotatablein the opposite direction, and the cage is frictionally held by one ormore drag devices 48, herein two, which permit forward rotation of thecage and the sleeve 29 with the shaft 31 but anchor the cage againstreverse turning so that such turning rotates the planetary gear, ratherthan the cage. Such rotation of the planetary gear, in turn, is used toproduce the declutching signal after a selected amount of reverserotation of the shaft 31. 2

More specifically, the drag devices 48 comprise two generally V-shapedspring plates which are mounted on two pins 49 projecting acrossopposite sides of the cage from a stationary mounting disk 50 that issupported on a sleeve 51 bolted to the lower wall of the case 12 aroundthe bearing 21. The spring plates are pressed against the cylindricalsidewall 47 to exert sufficient frictional drag thereon to immobilizethe cage during reverse rotation of the drive shaft 31 and turning ofthe planetary gear within the gage, but slip on the cage to permit thelatter to turn with the drive shaft during forward shaft rotation, whenrelative rotation of the gears 43 and 45 is prevented.

In the present instance, a second pinion, or output gear 52, is looselydisposed around the drive shaft 31 within the cage, beside the firstpinion gear 45, a second planetary gear 53 is mounted on the gear shaft44 forrotation therewith, normally in meshing engagement with the outputgear 52, and a spacer 54, preferably a gearsimilar to the gear 53, isloosely mounted on the gear shaft between the two gears 43 and 53.Reverse rotation of the pinion gear 45 with the drive shaft thus rotatesthe planetary gears 43 and 53 together, and the latter-.,gear rotatesthe output gear 52 about the pin 55 from one of the endwalls 41 of thecage, in advance of the pin 55 in the forward direction. By blockingrotation of the gear 52, these pins act through the gear 53, the gearshaft 44,. the gear 43 and the pinion gear 45 to prevent relativerotation of the shaft 31 and the cage. A filled tooth (not shown) on theoutput gear will serve the same function. r

In any event, forward rotation of the drive shaft 31 turns the piniongear 45 thereon and tends to rotate the planetary gears 43 and 53, andthe gear 53 simultaneously tends to turn the output gear 52. When thestop pin 55 is in blocking engagement with the pin 57, forward rotationof the gears is prevented, and the cage is rotated with the drive shaftagainst the drag of the springs 48. Whenever the drive shaft 31 beginsto turn reversely (that is, upon reversal of the direction of linealmotion of the drilling tool), the gears 43 and 53 are free to turn inthe reverse direction and to move the stop pin 55 away from the pin 57,while the cage is frictionally anchored against turning reversely. As aresult, the cage and the sleeve 29 remain stationary, leaving theodometer 11 with a reading indicating the previously achieved depth ofpenetration, as the drilling tool is raised and the shaft 31 begins toturn in reverse,and such reverse turning rotates the output gear 52reversely, clockwise as viewed in FIG. 3.

As shown most clearly in FIG. 2, a signal am 58 is mounted on the shaft31 immediately beneath the oneway coupling 39 by means of a hub 59 inthe form of a sleeve which is loosely telescoped over the shaft, andthis hub abuts against the lower end of a sleeve 60 constituting anextension of the hub of the output gear 52, and rotatable with theoutput gear about the shaft 31. The hub 59 is pressed against theextension 60 by a coiled spring 61 fitted over the shaft and compressedbetween the hub and a collar 62 around the shaft below the spring. Thisforms a slip-friction coupling between the signal arm 58 and the outputgear 52, tending to turn the arm with the gear.

During forward operation of the shaft assembly, during which the outputgear rotates forwardly with the shaft 31, the signal arm 58 is heldstationary in a preselected idle position, shown in full lines in FIGS.2 and 4, by a stop pin 63 stationarily mounted on the mounting disk 50and projecting across the path of the signal arm to block forwardrotation of the arm. Thus, the hub 59 slips relative to the extension 60of the output gear 52, and the arm remains in the idle position. Whenthe shaft 31 begins to turn reversely,'however, the reverse rotation ofthe output gear 52 begins to rotate the hub 59 of the arm reversely,clockwise as indicated by the arrow 64 in FIG. 4, thereby swinging thearm clockwise away from the stop pin 63 at a rate determined by the rateof reverse rotation of the shaft and the ratio of the gearing betweenthe shaft and the arm.

Spaced a preselected angular distance from the idle position ofthe-signal arm 58 is a stationary nozzle 65 on the disk 50 to which acontinuous flow of air is supplied through -a passage 67. The orifice ofthis nozzle is positioned to be blocked by the signal arm after aselected amount of rotation of the latter from its idle position to theposition shown in broken lines in FIGS. 2 and 4, and the change in backpressure in the nozzle and in its supply passage 67 is the signal whichis used to actuate the air cylinder 24 in a manner which is within theskill of the art and is illustrated in the simplified control circuitryin FIG. 6 to be described. The

amount of rotation of the arm 58 required to effect declutching isvariable, according to the amount of reverse shaft rotation desiredbefore de-clutching is effected, simply by varying the angular spacingof the pin 63 and the nozzle 65. 1

When the cylinder 24 is actuated, its piston rod 25 is extended to rockthe arm 27 clockwise, as viewed in FIG. 1, thereby pushing downwardly onthe collar 30, shifting the output member 20 of the clutch 18 away fromthe input member 19, and simultaneously shifting the sleeve 29 and theone-way coupling 39 axially along the shaft 31, downwardly as viewed inthe drawings. Such downward movement is permitted by the pin-and slotconnection 32, 33 between shaft 31 and the hub 20a of the clutch member20, and by the spring 34 compressed within the sleeve between theshoulders 35 and 37, the latter shoulder being formed by the end of thehub of the pinion gear 45. In addition to disengaging the clutch, thisaxial motion of the sleeve 29 shifts the planetary gear 53 axiallyrelative to the output gear 52 far enough to disengage the output gearfrom the planetary gear 53, shifting it into engagement with the spacergear 54 which is loosely mounted on the gear shaft 44.

As shown most clearly in FIGS. 2 and 5, a main spring 68 is wrappedspirally around the hub extension 60 in an annular recess defined by aflanged sleeve 69 telescoped over the hub extension and fastened to thelower endwall 41 of the cage. The spring is anchored at one end to thehub extension and at the other end to the flanged sleeve (See FIG. 5),so that rotation of the output gear 52 during reverse rotation of theshaft 51 winds up the spring as the signal arm 58 is rotated toward thenozzle 65.

Then, when the shaft assembly is de-clutched and the gear 53 is shiftedout of engagement with the output gear 52, the latter is released andthe main spring 68 is freed to unwind. In so doing, the spring returnsthe signal arm 58 and the output gear 52 to their starting positionswith the pins 55 and 57 in abutting engagement and with the signal arm58 against the pin 63.

In this condition, the driving apparatus is ready for immediatereactivation, simply by re-engaging the clutch 18 when drilling is to beresumed. Any movement of the drilling tool prior to such reactivation,either upor down, has no effect on the odometer 11 an thus cannotdisturb the footage total that was logged prior to the initial reversal.

In general, the control circuitry, as shown in simplified form in FIG.6, includes a source 70 of signal air at a suitable pressure, such as 20pounds per square inch (P.S.I.), connected by a restricted line 71 to apilot valve 72 from which the air flows through line 67 to the nozzle65. When the orifice of the nozzle is blocked by the signal arm 38, theresulting increase in back pressure in the line 67 actuates the pilotvalve 72 in a conventional manner to admit air from a second source 73,at a suitable pressure such as 90 P.S.I., into a line 74 leading to acontrol valve 75 at the drillers station.

When line 74 is pressurized, the plunger 77 of the drillers controlvalve 75 is thrown out, and actuating pressure from the high-pressuresource 73 is introduced through a branch line 78 and the drillerscontrol valve 75 to a line 79 leading to the de-clutch cylinder 24. Thisactuates the de-clutch cylinder to disengage the clutch 18,simultaneously returning the signal arm 58 to its idle position. The aircylinder remains in the de-clutch condition, however, as long as theplunger 77 of the drillers valve remains out. Accordingly, the odometerremains deactivated during any subsequent raising and lowering of thedrill string. Pressurization of the line 79 also serves to activate asignal device, such as a light 80 at the drillers station, indicatingthat the odometer is de-clutched.

When the drill bit has been returned to the bottom of the hole anddrilling is, to be resumed, the driller simply pushes the plunger 77 inas he initiates drilling. This releases the actuating pressure on thede-clutch cylinder 24 and permits its return spring to retract thepiston rod 25, thus engaging the clutch 18 to reactivate the odometer114%: the same time, the signal light 80 is turned ratus and prepare thesame for immediate reactivation when drilling is to be resumed.Moreover, the apparatus is relatively simple and reliable inconstruction and operation. It also will be apparent that, while aparticular form has been illustrated and described, variousmodifications and changes may be made without departing from the spiritand scope of the invention.

I claim:

1. Apparatus for driving a drilling recorder during drilling travel of adrilling tool, deactivating the recorder during reverse travel of thetool, and reactivating the recorder for the resumption of drillingtravel, said apparatus comprising:

a drive shaft;

a selectively engageable and disengageable clutch member on said shaftfor coupling and uncoupling the latter and, when the shaft is coupled,turning the shaft at a rate correlated with the linear travel of thetool;

a sleeve telescoped over said shaft and rotatable about the shaft, saidsleeve having means thereon for driving the recorder as the sleeverotates;

a cage connected to said sleeve for rotation therewith, and having aninterior into which said shaft projects;

a pinion gear mounted on said shaft within said cage,

and rotatable with said shaft;

a planetary gear mounted on said cage and meshing with said pinion gearto turn said cage and said sleeve as said pinion gear rotates;

means forming a stop and preventing rotation of said pinion gearrelative to said planetary gear in one direction from a preselectedangular relation of said gears, thereby locking said cage and saidsleeve to said shaft for rotation therewith as said shaft is turned inone direction during drilling travel of the tool, but permittingrotation of said pinion gear in the opposite direction, during reversetravel-of the tool from any attained position;

means preventing rotation of said cage and said sleeve during rotationof said pinion gear in said opposite direction but permitting rotationof said cage and said sleeve with said shaft during rotation of saidshaft in said one direction, thereby to drive the recorder for recordingof drilling travel while preventing reverse operation of the recorderduring reverse travel of the tool; a gear assembly including an outputgear driven by said planetary gear as said pinion gear turns relative tosaid cage during reverse operation of said shaft;

a signal arm having a hub telescoped onto said shaft;

a slip-friction coupling between said output gear and said hub urgingsaid hub to turn with said output gear but permitting slipping of saidhub relative to the'output gear;

a second stop holding said arm in a selected idle position as said shaftis turned in said one direction during drilling travel of the tool, butpermitting rotation of said hub and said arm with said output gear outof said idle position during reverse travel of the tool;

means operated by said signal arm after a selected amount of saidreverse operation to produce a signal for disengaging said clutchmember, thereby to deactivate said recorder by uncoupling said shaft;

spring means operable upon disengagement of said clutch to return saidsignal arm to said idle position and said gears to said angularrelation;

and selectively operable means for re-engaging said clutch member whenthe tool has been returned to any previously attained drilling positionfor resumption recording.

2. Apparatus for driving a recording instrument during forward travel ofa drilling tool, deactivating the instrument during reverse travel ofthe tool, and reactivating the instrument for the resumption of forwardtravel, said apparatus comprising:

a drive shaft;

selectively engageable and disengageable clutch means for coupling anduncoupling said drive shaft and operable when coupled to turn the latterat a rate corresponding to the lineal travel of said drilling tool;

a drive coupling supported on said drive shaft and connectible to theinstrument to drive the latter as said drive coupling turns with saidshaft, said drive coupling being rotatable relative to said shaft;

means connecting said drive coupling to said shaft for rotation of thecoupling and the shaft together in a preselected angular relation in onedirection of rotation of the shaft, thereby to drive the instrumentduring forward travel of said tool, but permitting reverse rotation ofthe shaft relative to the coupling from said angular relation duringreverse travel of said tool from an attained drilling position whilesaid clutch is engaged;

means for preventing reverse rotation of a said coupling with saidshaft, thereby preventing reverse operation of the instrument;

means responsive to a preselected amount of said reverse rotation ofsaid shaft to actuate said clutch and uncouple said shaft, therebydeactivating said driving apparatus;

and meansfor re-engaging said clutch when the drilling tool has beenreturned to the previously attained drilling position preparatory toresumption of drilling travel.

3. Apparatus for driving a recording instrument during forward travel ofa drilling tool, deactivating the instrument during reverse travel, andreactivating the instrument for the resumption of forward travel, saidapparatus comprising: a drive-member selectively engageable anddisengageable clutch means for coupling and uncoupling said drive memberand operable when coupled to drive the latter reversibly at a ratecorresponding to the lineal travel of the drilling tool; a drivecoupling connectible to the instrument to drive the instrument andrecord forward travel of the drilling tool;

means connecting said drive coupling to said drive member for driving ofthe coupling by the drive member while the latter is driven in onedirection during forward operation of the drilling tool;

means responsive to movement of said drive member in the other directionduring reverse operation of the drilling tool to produce a signal fordisengaging said clutch means and leaving said drive coupling in aposition corresponding to the greatest penetration of the drilling tool;

and means for re-engaging said clutch means when the drilling tool hasbeen retumedto the previously attained position of greatest penetration,preparatory to resumption of drilling.

4. Driving apparatus as defined in claim 3 wherein said drive member isa shaft supported for reversible rotation, and said drive coupling isrotatably mounted on said shaft, said connecting means comprising aoneway coupling between said shaft and said drive coupling for turningthe latter with said shaft during rotation thereof in said onedirection, and permitting relative rotation of the shaft in said otherdirection.

5. Driving apparatus as defined in claim 4 inwhich said responsive meansinclude a signal arm mounted on said shaft, means holding said signalarm in a preselected idle position during rotation of said shaft andsaid coupling in said one direction, means for turning said signal armout of said idle position in response to rotation of said shaft in saidother direction, and signal means for producing said signal when saidarm is turned into a second position angularly spaced from said idleposition.

6. Driving apparatus as defined in claim 5 in which said shaft carries apinion gear, and said drive coupling includes a cage having a planetarygear meshing with said pinion gear, means preventing rotation of saidplanetary gear by said pinion gear during rotation of said shaft in saidone direction, whereby said pinion drives said cage with said shaftduring forward rotation, and means permitting such driving of said cagebut preventing reverse driving thereof.

7. Driving apparatus as defined in claim 6 in which said means forturning said signal arm includes additional gearing driven by saidplaneatary gear during reverse driving of said cage, and a slip-frictionclutch between said additional gearing and said signal arm permittingsaid arm to be held in said idle position during forward rotation ofsaid shaft and said cage.

8. Driving apparatus as defined in claim 5 in which said signalmeanscomprise an orifice positioned along the path of said signal arm to beblocked thereby when the arm is in said second position, means forsupplying a flow of signal an under pressure to said orifice, and meansfor responsive to an increase in the back pressure of said signal andresulting from blocking of the orifice by said arm, and operable todisengage said clutch means.

9. Driving apparatus as defined in claim 8 in which said clutch meansinclude a fluid-operated actuating cylinder for coupling and uncouplingsaid drive member, and wherein said means responsive to an increase insaid back pressure include a pilot valve operated by said increase, andmeans controlled by said pilot valve for supplying actuating fluid tosaid cylinder.

10. Driving apparatus as defined in claim 9 in which said last-mentionedmeans include drillers control valve operated automatically by saidpilot valve to actuate said cylinder and uncouple said drive member, andhaving a manually actuator for re-engaging said clutch means whendrilling is to be resumed.

11. Driving apparatus as defined in claim 5 further including springmeans for returning said signal arm to said idle position upondisengagement of said clutch means.

1. Apparatus for driving a drilling recorder during drilling travel of adrilling tool, deactivating the recorder during reverse travel of thetool, and reactivating the recorder for the resumption of drillingtravel, said apparatus comprising: a drive shaft; a selectivelyengageable and disengageable clutch member on said shaft for couplingand uncoupling the latter and, when the shaft is coupled, turning theshaft at a rate correlated with the linear travel of the tool; a sleevetelescoped over said shaft and rotatable about the shaft, said sleevehaving means thereon for driving the recorder as the sleeve rotates; acage connected to said sleeve for rotation therewith, and having aninterior into which said shaft projects; a pinion gear mounted on saidshaft within said cage, and rotatable with said shaft; a planetary gearmounted on said cage and meshing with said pinion gear to turn said cageand said sleeve as said pinion gear rotates; means forming a stop andpreventing rotation of said pinion gear relative to said planetary gearin one direction from a preselected angular relation of said gears,thereby locking said cage and said sleeve to said shaft for rotationtherewith as said shaft is turned in one direction during drillingtravel of the tool, but permitting rotation of said pinion gear in theopposite direction, during reverse travel of the tool from any attainedposition; means preventing rotation of said cage and said sleeve duringrotation of said pinion gear in said opposite direction but permittingrotation of said cage and said sleeve with said shaft during rotation ofsaid shaft in said one direction, thereby to drive the recorder forrecording of drilling travel while preventing reverse operation of therecorder during reverse travel of the tool; a gear assembly including anoutput gear driven by said planetary gear as said pinion gear turnsrelative to said cage during reverse operation of said shaft; a signalarm having a hub telescoped onto said shaft; a slip-friction couplingbetween said output gear and said hub urging said hub to turn with saidoutput gear but permitting slipping of said hub relative to the outputgear; a second stop holding said arm in a selected idle position as saidshaft is turned in said one direction during drilling travel of thetool, but permitting rotation of said hub and said arm with said outputgear out of said idle position during reverse travel of the tool; meansoperated by said signal arm after a selected amount of said reverseoperation to produce a signal for disengaging said clutch member,thereby to deactivate said recorder by uncoupling said shaft; springmeans operable upon disengagement of said clutch to return said signalarm to said idle position and said gears to said angular relation; andselectively operable means for re-engaging said clutch member when thetool has been returned to any previously attained drilling position forresumption recording.
 2. Apparatus for driving a recording instrumentduring forward travel of a drilling tool, deactivating the instrumentduring reverse travel of the tool, and reactivating the instrument forthe resumption of forward travel, said apparatus comprising: a driveshaft; selectively engageable and disengageable clutch means forcoupling and uncoupling said drive shaft and operable when coupled toturn the latter at a rate corresponding to the lineal travel of saiddrilling tool; a drive coupling supported on said drive shaft andconnectible to the instrument to drive the latter as said drive couplingturns with said shaft, said drive coupling being rotatable relative tosaid shaft; means connecting said drive coupling to said shaft forrotation of the coupling and the shaft together in a preselected angularrelation in one direction of rotation of the shaft, thereby to drive theinstrument during forward travel oF said tool, but permitting reverserotation of the shaft relative to the coupling from said angularrelation during reverse travel of said tool from an attained drillingposition while said clutch is engaged; means for preventing reverserotation of a said coupling with said shaft, thereby preventing reverseoperation of the instrument; means responsive to a preselected amount ofsaid reverse rotation of said shaft to actuate said clutch and uncouplesaid shaft, thereby deactivating said driving apparatus; and means forre-engaging said clutch when the drilling tool has been returned to thepreviously attained drilling position preparatory to resumption ofdrilling travel.
 3. Apparatus for driving a recording instrument duringforward travel of a drilling tool, deactivating the instrument duringreverse travel, and reactivating the instrument for the resumption offorward travel, said apparatus comprising: a drive member selectivelyengageable and disengageable clutch means for coupling and uncouplingsaid drive member and operable when coupled to drive the latterreversibly at a rate corresponding to the lineal travel of the drillingtool; a drive coupling connectible to the instrument to drive theinstrument and record forward travel of the drilling tool; meansconnecting said drive coupling to said drive member for driving of thecoupling by the drive member while the latter is driven in one directionduring forward operation of the drilling tool; means responsive tomovement of said drive member in the other direction during reverseoperation of the drilling tool to produce a signal for disengaging saidclutch means and leaving said drive coupling in a position correspondingto the greatest penetration of the drilling tool; and means forre-engaging said clutch means when the drilling tool has been returnedto the previously attained position of greatest penetration, preparatoryto resumption of drilling.
 4. Driving apparatus as defined in claim 3wherein said drive member is a shaft supported for reversible rotation,and said drive coupling is rotatably mounted on said shaft, saidconnecting means comprising a one-way coupling between said shaft andsaid drive coupling for turning the latter with said shaft duringrotation thereof in said one direction, and permitting relative rotationof the shaft in said other direction.
 5. Driving apparatus as defined inclaim 4 in which said responsive means include a signal arm mounted onsaid shaft, means holding said signal arm in a preselected idle positionduring rotation of said shaft and said coupling in said one direction,means for turning said signal arm out of said idle position in responseto rotation of said shaft in said other direction, and signal means forproducing said signal when said arm is turned into a second positionangularly spaced from said idle position.
 6. Driving apparatus asdefined in claim 5 in which said shaft carries a pinion gear, and saiddrive coupling includes a cage having a planetary gear meshing with saidpinion gear, means preventing rotation of said planetary gear by saidpinion gear during rotation of said shaft in said one direction, wherebysaid pinion drives said cage with said shaft during forward rotation,and means permitting such driving of said cage but preventing reversedriving thereof.
 7. Driving apparatus as defined in claim 6 in whichsaid means for turning said signal arm includes additional gearingdriven by said planeatary gear during reverse driving of said cage, anda slip-friction clutch between said additional gearing and said signalarm permitting said arm to be held in said idle position during forwardrotation of said shaft and said cage.
 8. Driving apparatus as defined inclaim 5 in which said signal means comprise an orifice positioned alongthe path of said signal arm to be blocked thereby when the arm is insaid second position, means for supplying a flow of signal an underpressure to said orifice, And means for responsive to an increase in theback pressure of said signal and resulting from blocking of the orificeby said arm, and operable to disengage said clutch means.
 9. Drivingapparatus as defined in claim 8 in which said clutch means include afluid-operated actuating cylinder for coupling and uncoupling said drivemember, and wherein said means responsive to an increase in said backpressure include a pilot valve operated by said increase, and meanscontrolled by said pilot valve for supplying actuating fluid to saidcylinder.
 10. 10. Driving apparatus as defined in claim 9 in which saidlast-mentioned means include driller''s control valve operatedautomatically by said pilot valve to actuate said cylinder and uncouplesaid drive member, and having a manually actuator for re-engaging saidclutch means when drilling is to be resumed.
 11. Driving apparatus asdefined in claim 5 further including spring means for returning saidsignal arm to said idle position upon disengagement of said clutchmeans.